lib: Add VFS0050 driver

New driver for 138a:0050 device https://bugs.freedesktop.org/show_bug.cgi?id=91616
2025-11-15 07:38:12 +00:00 · 2016-01-19 14:26:29 +03:00
parent 76269decdd
commit 49a46668ad
7 changed files with 1198 additions and 1 deletions
--- a/libfprint/drivers/vfs0050.c
+++ b/libfprint/drivers/vfs0050.c
@@ -0,0 +1,791 @@
+/*
+ * Validity VFS0050 driver for libfprint
+ * Copyright (C) 2015-2016 Konstantin Semenov <zemen17@gmail.com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#define FP_COMPONENT "vfs0050"
+
+#include <errno.h>
+#include <string.h>
+#include <fp_internal.h>
+#include <assembling.h>
+#include "driver_ids.h"
+
+#include "vfs0050.h"
+
+/* USB functions */
+
+/* Callback for async_write */
+static void async_write_callback(struct libusb_transfer *transfer)
+{
+	struct fpi_ssm *ssm = transfer->user_data;
+	struct fp_img_dev *idev = ssm->priv;
+
+	int transferred = transfer->actual_length, error =
+	    transfer->status, len = transfer->length;
+
+	if (error != 0) {
+		fp_err("USB write transfer: %s", libusb_error_name(error));
+		fpi_imgdev_session_error(idev, -EIO);
+		fpi_ssm_mark_aborted(ssm, -EIO);
+		return;
+	}
+
+	if (transferred != len) {
+		fp_err("Written only %d of %d bytes", transferred, len);
+		fpi_imgdev_session_error(idev, -EIO);
+		fpi_ssm_mark_aborted(ssm, -EIO);
+		return;
+	}
+
+	fpi_ssm_next_state(ssm);
+}
+
+/* Send data to EP1, the only out endpoint */
+static void async_write(struct fpi_ssm *ssm, void *data, int len)
+{
+	struct fp_img_dev *idev = ssm->priv;
+	struct libusb_device_handle *udev = idev->udev;
+	struct vfs_dev_t *vdev = idev->priv;
+
+	vdev->transfer = libusb_alloc_transfer(0);
+	vdev->transfer->flags |= LIBUSB_TRANSFER_FREE_TRANSFER;
+	libusb_fill_bulk_transfer(vdev->transfer, udev, 0x01, data, len,
+				  async_write_callback, ssm, VFS_USB_TIMEOUT);
+	libusb_submit_transfer(vdev->transfer);
+}
+
+/* Callback for async_read */
+static void async_read_callback(struct libusb_transfer *transfer)
+{
+	struct fpi_ssm *ssm = transfer->user_data;
+	struct fp_img_dev *idev = ssm->priv;
+
+	int transferred = transfer->actual_length, error =
+	    transfer->status, len = transfer->length;
+	int ep = transfer->endpoint;
+
+	if (error != 0) {
+		fp_err("USB read transfer on endpoint %d: %s", ep - 0x80,
+		       libusb_error_name(error));
+		fpi_imgdev_session_error(idev, -EIO);
+		fpi_ssm_mark_aborted(ssm, -EIO);
+		return;
+	}
+
+	if (transferred != len) {
+		fp_err("Received %d instead of %d bytes", transferred, len);
+		fpi_imgdev_session_error(idev, -EIO);
+		fpi_ssm_mark_aborted(ssm, -EIO);
+		return;
+	}
+
+	fpi_ssm_next_state(ssm);
+}
+
+/* Receive data from the given ep and compare with expected */
+static void async_read(struct fpi_ssm *ssm, int ep, void *data, int len)
+{
+	struct fp_img_dev *idev = ssm->priv;
+	struct libusb_device_handle *udev = idev->udev;
+	struct vfs_dev_t *vdev = idev->priv;
+
+	ep |= LIBUSB_ENDPOINT_IN;
+
+	vdev->transfer = libusb_alloc_transfer(0);
+	vdev->transfer->flags |= LIBUSB_TRANSFER_FREE_TRANSFER;
+
+	/* 0x83 is the only interrupt endpoint */
+	if (ep == EP3_IN)
+		libusb_fill_interrupt_transfer(vdev->transfer, udev, ep, data,
+					       len, async_read_callback, ssm,
+					       VFS_USB_TIMEOUT);
+	else
+		libusb_fill_bulk_transfer(vdev->transfer, udev, ep, data, len,
+					  async_read_callback, ssm,
+					  VFS_USB_TIMEOUT);
+	libusb_submit_transfer(vdev->transfer);
+}
+
+/* Callback for async_read */
+static void async_abort_callback(struct libusb_transfer *transfer)
+{
+	struct fpi_ssm *ssm = transfer->user_data;
+	struct fp_img_dev *idev = ssm->priv;
+
+	int transferred = transfer->actual_length, error = transfer->status;
+	int ep = transfer->endpoint;
+
+	/* In normal case endpoint is empty */
+	if (error == LIBUSB_TRANSFER_TIMED_OUT) {
+		fpi_ssm_next_state(ssm);
+		return;
+	}
+
+	if (error != 0) {
+		fp_err("USB write transfer: %s", libusb_error_name(error));
+		fpi_imgdev_session_error(idev, -EIO);
+		fpi_ssm_mark_aborted(ssm, -EIO);
+		return;
+	}
+
+	/* Don't stop process, only print warning */
+	if (transferred > 0)
+		fp_warn("Endpoint %d had extra %d bytes", ep - 0x80,
+			transferred);
+
+	fpi_ssm_jump_to_state(ssm, ssm->cur_state);
+}
+
+/* Receive data from the given ep and compare with expected */
+static void async_abort(struct fpi_ssm *ssm, int ep)
+{
+	struct fp_img_dev *idev = ssm->priv;
+	struct libusb_device_handle *udev = idev->udev;
+	struct vfs_dev_t *vdev = idev->priv;
+
+	int len = VFS_USB_BUFFER_SIZE;
+	unsigned char *data = g_malloc(VFS_USB_BUFFER_SIZE);
+
+	ep |= LIBUSB_ENDPOINT_IN;
+
+	vdev->transfer = libusb_alloc_transfer(0);
+	vdev->transfer->flags |=
+	    LIBUSB_TRANSFER_FREE_TRANSFER | LIBUSB_TRANSFER_FREE_BUFFER;
+
+	/* 0x83 is the only interrupt endpoint */
+	if (ep == EP3_IN)
+		libusb_fill_interrupt_transfer(vdev->transfer, udev, ep, data,
+					       len, async_abort_callback, ssm,
+					       VFS_USB_ABORT_TIMEOUT);
+	else
+		libusb_fill_bulk_transfer(vdev->transfer, udev, ep, data, len,
+					  async_abort_callback, ssm,
+					  VFS_USB_ABORT_TIMEOUT);
+	libusb_submit_transfer(vdev->transfer);
+}
+
+/* Image processing functions */
+
+/* Pixel getter for fpi_assemble_lines */
+static unsigned char vfs0050_get_pixel(struct fpi_line_asmbl_ctx *ctx,
+				       GSList * line, unsigned int x)
+{
+	return ((struct vfs_line *)line->data)->data[x];
+}
+
+/* Deviation getter for fpi_assemble_lines */
+static int vfs0050_get_difference(struct fpi_line_asmbl_ctx *ctx,
+				  GSList * line_list_1, GSList * line_list_2)
+{
+	struct vfs_line *line1 = line_list_1->data;
+	struct vfs_line *line2 = line_list_2->data;
+	const int shift = (VFS_IMAGE_WIDTH - VFS_NEXT_LINE_WIDTH) / 2 - 1;
+	int res = 0;
+	for (int i = 0; i < VFS_NEXT_LINE_WIDTH; ++i) {
+		int x =
+		    (int)line1->next_line_part[i] - (int)line2->data[shift + i];
+		res += x * x;
+	}
+	return res;
+}
+
+#define VFS_NOISE_THRESHOLD 40
+
+/* Checks whether line is noise or not using hardware parameters */
+static char is_noise(struct vfs_line *line)
+{
+	int val1 = line->noise_hash_1;
+	int val2 = line->noise_hash_2;
+	if (val1 > VFS_NOISE_THRESHOLD
+	    && val1 < 256 - VFS_NOISE_THRESHOLD
+	    && val2 > VFS_NOISE_THRESHOLD && val2 < 256 - VFS_NOISE_THRESHOLD)
+		return 1;
+	return 0;
+}
+
+/* Parameters for fpi_assemble_lines */
+static struct fpi_line_asmbl_ctx assembling_ctx = {
+	.line_width = VFS_IMAGE_WIDTH,
+	.max_height = VFS_MAX_HEIGHT,
+	.resolution = 10,
+	.median_filter_size = 25,
+	.max_search_offset = 100,
+	.get_deviation = vfs0050_get_difference,
+	.get_pixel = vfs0050_get_pixel,
+};
+
+/* Processes image before submitting */
+static struct fp_img *prepare_image(struct vfs_dev_t *vdev)
+{
+	int height = vdev->bytes / VFS_LINE_SIZE;
+
+	/* Noise cleaning. IMHO, it works pretty well
+	   I've not detected cases when it doesn't work or cuts a part of the finger
+	   Noise arises at the end of scan when some water remains on the scanner */
+	while (height > 0) {
+		if (!is_noise(vdev->lines_buffer + height - 1))
+			break;
+		--height;
+	}
+	if (height > VFS_MAX_HEIGHT)
+		height = VFS_MAX_HEIGHT;
+
+	/* If image is not good enough */
+	if (height < VFS_IMAGE_WIDTH)
+		return NULL;
+
+	/* Building GSList */
+	GSList *lines = NULL;
+	for (int i = height - 1; i >= 0; --i)
+		lines = g_slist_prepend(lines, vdev->lines_buffer + i);
+
+	/* Perform line assembling */
+	struct fp_img *img = fpi_assemble_lines(&assembling_ctx, lines, height);
+
+	g_slist_free(lines);
+	return img;
+}
+
+/* Processes and submits image after fingerprint received */
+static void submit_image(struct fp_img_dev *idev)
+{
+	struct vfs_dev_t *vdev = idev->priv;
+
+	/* We were not asked to submit image actually */
+	if (!vdev->active)
+		return;
+
+	struct fp_img *img = prepare_image(vdev);
+
+	if (!img)
+		fpi_imgdev_abort_scan(idev, FP_VERIFY_RETRY_TOO_SHORT);
+	else
+		fpi_imgdev_image_captured(idev, img);
+
+	/* Finger not on the scanner */
+	fpi_imgdev_report_finger_status(idev, 0);
+}
+
+/* Proto functions */
+
+/* SSM loop for clear_ep2 */
+static void clear_ep2_ssm(struct fpi_ssm *ssm)
+{
+	struct fp_img_dev *idev = ssm->priv;
+
+	short result;
+	char command04 = 0x04;
+
+	switch (ssm->cur_state) {
+	case SUBSM1_COMMAND_04:
+		async_write(ssm, &command04, sizeof(command04));
+		break;
+
+	case SUBSM1_RETURN_CODE:
+		async_read(ssm, 1, &result, sizeof(result));
+		break;
+
+	case SUBSM1_ABORT_2:
+		async_abort(ssm, 2);
+		break;
+
+	default:
+		fp_err("Unknown SUBSM1 state");
+		fpi_imgdev_session_error(idev, -EIO);
+		fpi_ssm_mark_aborted(ssm, -EIO);
+	}
+}
+
+/* Send command to clear EP2 */
+static void clear_ep2(struct fpi_ssm *ssm)
+{
+	struct fp_img_dev *idev = ssm->priv;
+
+	struct fpi_ssm *subsm =
+	    fpi_ssm_new(idev->dev, clear_ep2_ssm, SUBSM1_STATES);
+	subsm->priv = idev;
+	fpi_ssm_start_subsm(ssm, subsm);
+}
+
+static void send_control_packet_ssm(struct fpi_ssm *ssm)
+{
+	struct fp_img_dev *idev = ssm->priv;
+	struct vfs_dev_t *vdev = idev->priv;
+
+	short result;
+	unsigned char *commit_result = NULL;
+
+	switch (ssm->cur_state) {
+	case SUBSM2_SEND_CONTROL:
+		async_write(ssm, vdev->control_packet, VFS_CONTROL_PACKET_SIZE);
+		break;
+
+	case SUBSM2_RETURN_CODE:
+		async_read(ssm, 1, &result, sizeof(result));
+		break;
+
+	case SUBSM2_SEND_COMMIT:
+		/* next_receive_* packets could be sent only in pair */
+		if (vdev->control_packet == next_receive_1) {
+			vdev->control_packet = next_receive_2;
+			fpi_ssm_jump_to_state(ssm, SUBSM2_SEND_CONTROL);
+			break;
+		}
+		/* commit_out in Windows differs in each commit, but I send the same each time */
+		async_write(ssm, commit_out, sizeof(commit_out));
+		break;
+
+	case SUBSM2_COMMIT_RESPONSE:
+		commit_result = g_malloc(VFS_COMMIT_RESPONSE_SIZE);
+		async_read(ssm, 1, commit_result, VFS_COMMIT_RESPONSE_SIZE);
+		break;
+
+	case SUBSM2_READ_EMPTY_INTERRUPT:
+		/* I don't know how to check result, it could be different */
+		g_free(commit_result);
+
+		async_read(ssm, 3, vdev->interrupt, VFS_INTERRUPT_SIZE);
+		break;
+
+	case SUBSM2_ABORT_3:
+		/* Check that interrupt is empty */
+		if (memcmp
+		    (vdev->interrupt, empty_interrupt, VFS_INTERRUPT_SIZE)) {
+			fp_err("Unknown SUBSM2 state");
+			fpi_imgdev_session_error(idev, -EIO);
+			fpi_ssm_mark_aborted(ssm, -EIO);
+			break;
+		}
+		async_abort(ssm, 3);
+		break;
+
+	case SUBSM2_CLEAR_EP2:
+		/* After turn_on Windows doesn't clear EP2 */
+		if (vdev->control_packet != turn_on)
+			clear_ep2(ssm);
+		else
+			fpi_ssm_next_state(ssm);
+		break;
+
+	default:
+		fp_err("Unknown SUBSM2 state");
+		fpi_imgdev_session_error(idev, -EIO);
+		fpi_ssm_mark_aborted(ssm, -EIO);
+	}
+}
+
+/* Send device state control packet */
+static void send_control_packet(struct fpi_ssm *ssm)
+{
+	struct fp_img_dev *idev = ssm->priv;
+
+	struct fpi_ssm *subsm =
+	    fpi_ssm_new(idev->dev, send_control_packet_ssm, SUBSM2_STATES);
+	subsm->priv = idev;
+	fpi_ssm_start_subsm(ssm, subsm);
+}
+
+/* Clears all fprint data */
+static void clear_data(struct vfs_dev_t *vdev)
+{
+	g_free(vdev->lines_buffer);
+	vdev->lines_buffer = NULL;
+	vdev->memory = vdev->bytes = 0;
+}
+
+/* After receiving interrupt from EP3 */
+static void interrupt_callback(struct libusb_transfer *transfer)
+{
+	struct fpi_ssm *ssm = transfer->user_data;
+	struct fp_img_dev *idev = ssm->priv;
+	struct vfs_dev_t *vdev = idev->priv;
+
+	char *interrupt = vdev->interrupt;
+	int error = transfer->status, transferred = transfer->actual_length;
+
+	vdev->wait_interrupt = 0;
+
+	/* When we have cancelled transfer, error is ok actually */
+	if (!vdev->active && error == LIBUSB_TRANSFER_CANCELLED)
+		return;
+
+	if (error != 0) {
+		fp_err("USB read interrupt transfer: %s",
+		       libusb_error_name(error));
+		fpi_imgdev_session_error(idev, -EIO);
+		fpi_ssm_mark_aborted(ssm, -EIO);
+		return;
+	}
+
+	/* Interrupt size is VFS_INTERRUPT_SIZE bytes in all known cases */
+	if (transferred != VFS_INTERRUPT_SIZE) {
+		fp_err("Unknown interrupt size %d", transferred);
+		/* Abort ssm */
+		fpi_imgdev_session_error(idev, -EIO);
+		fpi_ssm_mark_aborted(ssm, -EIO);
+		return;
+	}
+
+	/* Standard interrupts */
+	if (memcmp(interrupt, interrupt1, VFS_INTERRUPT_SIZE) == 0 ||
+	    memcmp(interrupt, interrupt2, VFS_INTERRUPT_SIZE) == 0 ||
+	    memcmp(interrupt, interrupt3, VFS_INTERRUPT_SIZE) == 0) {
+		/* Go to the next ssm stage */
+		fpi_ssm_next_state(ssm);
+		return;
+	}
+
+	/* When finger is on the scanner before turn_on */
+	if (interrupt[0] == 0x01) {
+		fp_warn("Finger is already on the scanner");
+
+		/* Go to the next ssm stage */
+		fpi_ssm_next_state(ssm);
+		return;
+	}
+
+	/* Unknown interrupt; abort the session */
+	fp_err("Unknown interrupt '%02x:%02x:%02x:%02x:%02x'!",
+	       interrupt[0] & 0xff, interrupt[1] & 0xff, interrupt[2] & 0xff,
+	       interrupt[3] & 0xff, interrupt[4] & 0xff);
+
+	/* Abort ssm */
+	fpi_imgdev_session_error(idev, -EIO);
+	fpi_ssm_mark_aborted(ssm, -EIO);
+}
+
+static void receive_callback(struct libusb_transfer *transfer)
+{
+	struct fpi_ssm *ssm = transfer->user_data;
+	struct fp_img_dev *idev = ssm->priv;
+	struct vfs_dev_t *vdev = idev->priv;
+
+	int transferred = transfer->actual_length, error = transfer->status;
+
+	if (error != 0 && error != LIBUSB_TRANSFER_TIMED_OUT) {
+		fp_err("USB read transfer: %s", libusb_error_name(error));
+
+		fpi_imgdev_session_error(idev, -EIO);
+		fpi_ssm_mark_aborted(ssm, -EIO);
+		return;
+	}
+
+	/* Check if fingerprint data is over */
+	if (transferred == 0) {
+		fpi_ssm_next_state(ssm);
+	} else {
+		vdev->bytes += transferred;
+
+		/* We need more data */
+		fpi_ssm_jump_to_state(ssm, ssm->cur_state);
+	}
+}
+
+/* Stub to keep SSM alive when waiting an interrupt */
+static void wait_interrupt(void *data)
+{
+	struct fpi_ssm *ssm = data;
+	struct fp_img_dev *idev = ssm->priv;
+	struct vfs_dev_t *vdev = idev->priv;
+
+	/* Keep sleeping while this flag is on */
+	if (vdev->wait_interrupt)
+		fpi_ssm_jump_to_state(ssm, ssm->cur_state);
+}
+
+/* SSM stub to prepare device to another scan after orange light was on */
+static void another_scan(void *data)
+{
+	struct fpi_ssm *ssm = data;
+	fpi_ssm_jump_to_state(ssm, SSM_TURN_ON);
+}
+
+/* Another SSM stub to continue after waiting for probable vdev->active changes */
+static void scan_completed(void *data)
+{
+	struct fpi_ssm *ssm = data;
+	fpi_ssm_next_state(ssm);
+}
+
+/* Main SSM loop */
+static void activate_ssm(struct fpi_ssm *ssm)
+{
+	struct fp_img_dev *idev = ssm->priv;
+	struct libusb_device_handle *udev = idev->udev;
+	struct vfs_dev_t *vdev = idev->priv;
+
+	switch (ssm->cur_state) {
+	case SSM_INITIAL_ABORT_1:
+		async_abort(ssm, 1);
+		break;
+
+	case SSM_INITIAL_ABORT_2:
+		async_abort(ssm, 2);
+		break;
+
+	case SSM_INITIAL_ABORT_3:
+		async_abort(ssm, 3);
+		break;
+
+	case SSM_CLEAR_EP2:
+		clear_ep2(ssm);
+		break;
+
+	case SSM_TURN_OFF:
+		/* Set control_packet argument */
+		vdev->control_packet = turn_off;
+
+		send_control_packet(ssm);
+		break;
+
+	case SSM_TURN_ON:
+		if (!vdev->active) {
+			/* The only correct exit */
+			fpi_ssm_mark_completed(ssm);
+
+			if (vdev->need_report) {
+				fpi_imgdev_deactivate_complete(idev);
+				vdev->need_report = 0;
+			}
+			break;
+		}
+		/* Set control_packet argument */
+		vdev->control_packet = turn_on;
+
+		send_control_packet(ssm);
+		break;
+
+	case SSM_ASK_INTERRUPT:
+		/* Activated, light must be blinking now */
+
+		/* If we first time here, report that activate completed */
+		if (vdev->need_report) {
+			fpi_imgdev_activate_complete(idev, 0);
+			vdev->need_report = 0;
+		}
+
+		/* Asyncronously enquire an interrupt */
+		vdev->transfer = libusb_alloc_transfer(0);
+		vdev->transfer->flags |= LIBUSB_TRANSFER_FREE_TRANSFER;
+		libusb_fill_interrupt_transfer(vdev->transfer, udev, 0x83,
+					       vdev->interrupt,
+					       VFS_INTERRUPT_SIZE,
+					       interrupt_callback, ssm, 0);
+		libusb_submit_transfer(vdev->transfer);
+
+		/* This flag could be turned off only in callback function */
+		vdev->wait_interrupt = 1;
+
+		/* I've put it here to be sure that data is cleared */
+		clear_data(vdev);
+
+		fpi_ssm_next_state(ssm);
+		break;
+
+	case SSM_WAIT_INTERRUPT:
+		/* Check if user had interrupted the process */
+		if (!vdev->active) {
+			libusb_cancel_transfer(vdev->transfer);
+			fpi_ssm_jump_to_state(ssm, SSM_CLEAR_EP2);
+			break;
+		}
+
+		if (vdev->wait_interrupt)
+			fpi_timeout_add(VFS_SSM_TIMEOUT, wait_interrupt, ssm);
+		break;
+
+	case SSM_RECEIVE_FINGER:
+		if (vdev->memory == 0) {
+			/* Initialize fingerprint buffer */
+			g_free(vdev->lines_buffer);
+			vdev->memory = VFS_USB_BUFFER_SIZE;
+			vdev->lines_buffer = g_malloc(vdev->memory);
+			vdev->bytes = 0;
+
+			/* Finger is on the scanner */
+			fpi_imgdev_report_finger_status(idev, 1);
+		}
+
+		/* Increase buffer size while it's insufficient */
+		while (vdev->bytes + VFS_USB_BUFFER_SIZE > vdev->memory) {
+			vdev->memory <<= 1;
+			vdev->lines_buffer =
+			    (struct vfs_line *)g_realloc(vdev->lines_buffer,
+							 vdev->memory);
+		}
+
+		/* Receive chunk of data */
+		vdev->transfer = libusb_alloc_transfer(0);
+		vdev->transfer->flags |= LIBUSB_TRANSFER_FREE_TRANSFER;
+		libusb_fill_bulk_transfer(vdev->transfer, udev, 0x82,
+					  (void *)vdev->lines_buffer +
+					  vdev->bytes, VFS_USB_BUFFER_SIZE,
+					  receive_callback, ssm,
+					  VFS_USB_TIMEOUT);
+		libusb_submit_transfer(vdev->transfer);
+		break;
+
+	case SSM_SUBMIT_IMAGE:
+		submit_image(idev);
+		clear_data(vdev);
+
+		/* Wait for probable vdev->active changing */
+		fpi_timeout_add(VFS_SSM_TIMEOUT, scan_completed, ssm);
+		break;
+
+	case SSM_NEXT_RECEIVE:
+		if (!vdev->active) {
+			/* It's the last scan */
+			fpi_ssm_jump_to_state(ssm, SSM_CLEAR_EP2);
+			break;
+		}
+
+		/* Set control_packet argument */
+		vdev->control_packet = next_receive_1;
+
+		send_control_packet(ssm);
+		break;
+
+	case SSM_WAIT_ANOTHER_SCAN:
+		/* Orange light is on now */
+		fpi_timeout_add(VFS_SSM_ORANGE_TIMEOUT, another_scan, ssm);
+		break;
+
+	default:
+		fp_err("Unknown state");
+		fpi_imgdev_session_error(idev, -EIO);
+		fpi_ssm_mark_aborted(ssm, -EIO);
+	}
+}
+
+/* Driver functions */
+
+/* Callback for dev_activate ssm */
+static void dev_activate_callback(struct fpi_ssm *ssm)
+{
+	struct fp_img_dev *idev = ssm->priv;
+	struct vfs_dev_t *vdev = idev->priv;
+
+	vdev->ssm_active = 0;
+
+	fpi_ssm_free(ssm);
+}
+
+/* Activate device */
+static int dev_activate(struct fp_img_dev *idev, enum fp_imgdev_state state)
+{
+	struct vfs_dev_t *vdev = idev->priv;
+
+	/* Initialize flags */
+	vdev->active = 1;
+	vdev->need_report = 1;
+	vdev->ssm_active = 1;
+
+	struct fpi_ssm *ssm = fpi_ssm_new(idev->dev, activate_ssm, SSM_STATES);
+	ssm->priv = idev;
+	fpi_ssm_start(ssm, dev_activate_callback);
+	return 0;
+}
+
+/* Deactivate device */
+static void dev_deactivate(struct fp_img_dev *idev)
+{
+	struct vfs_dev_t *vdev = idev->priv;
+
+	if (!vdev->ssm_active) {
+		fpi_imgdev_deactivate_complete(idev);
+		return;
+	}
+
+	/* Initialize flags */
+	vdev->active = 0;
+	vdev->need_report = 1;
+}
+
+/* Callback for dev_open ssm */
+static void dev_open_callback(struct fpi_ssm *ssm)
+{
+	/* Notify open complete */
+	fpi_imgdev_open_complete((struct fp_img_dev *)ssm->priv, 0);
+	fpi_ssm_free(ssm);
+}
+
+/* Open device */
+static int dev_open(struct fp_img_dev *idev, unsigned long driver_data)
+{
+	/* Claim usb interface */
+	int error = libusb_claim_interface(idev->udev, 0);
+	if (error < 0) {
+		/* Interface not claimed, return error */
+		fp_err("could not claim interface 0");
+		return error;
+	}
+
+	/* Initialize private structure */
+	struct vfs_dev_t *vdev = g_malloc0(sizeof(struct vfs_dev_t));
+	idev->priv = vdev;
+
+	/* Clearing previous device state */
+	struct fpi_ssm *ssm = fpi_ssm_new(idev->dev, activate_ssm, SSM_STATES);
+	ssm->priv = idev;
+	fpi_ssm_start(ssm, dev_open_callback);
+	return 0;
+}
+
+/* Close device */
+static void dev_close(struct fp_img_dev *idev)
+{
+	/* Release private structure */
+	g_free(idev->priv);
+
+	/* Release usb interface */
+	libusb_release_interface(idev->udev, 0);
+
+	/* Notify close complete */
+	fpi_imgdev_close_complete(idev);
+}
+
+/* Usb id table of device */
+static const struct usb_id id_table[] = {
+	{.vendor = 0x138a,.product = 0x0050},
+	{0, 0, 0,},
+};
+
+/* Device driver definition */
+struct fp_img_driver vfs0050_driver = {
+	/* Driver specification */
+	.driver = {
+		   .id = VFS0050_ID,
+		   .name = FP_COMPONENT,
+		   .full_name = "Validity VFS0050",
+		   .id_table = id_table,
+		   .scan_type = FP_SCAN_TYPE_SWIPE,
+		   },
+
+	/* Image specification */
+	.flags = 0,
+	.img_width = VFS_IMAGE_WIDTH,
+	.img_height = -1,
+	.bz3_threshold = 24,
+
+	/* Routine specification */
+	.open = dev_open,
+	.close = dev_close,
+	.activate = dev_activate,
+	.deactivate = dev_deactivate,
+};